Flagellar regeneration in the biflagellated protozoan Chlamydomonas reinhardii is under investigation. The research is directed at understanding the cellular mechanisms for regulating this process. To this end we are studying regeneration in gametes of Chlamydomonas using several approaches. We are measuring the proteins that are synthesized during regeneration in both the cells and flagella. The labeled protein profiles are compared to proteins synthesized in non-regenerating cells by SDS-polyacrylamide gel electrophoresis. We are also investigating the types of poly (A) containing RNA that are synthesized in regenerating cultures of gametes. Lastly we are using several types of inhibitors whose action is currently understood to affect structural rather than metabolic activities of cells. These studies are coupled with ultrastructural studies on the effects of these inhibitors on the cells and flagella of Chlamydomonas.